If the supply of a predetermined quantity of electrical energy to any one of the electrical loads during this modulation period is effected by the generator emitting during a predetermined fraction of the modulation period an electrical signal the power whereof corresponds to that of this electrical load, it is known to use a method including a temporal distribution of the electrical signals sent by the generator in the modulation period in accordance with a predetermined distribution criterion.
For an alternating current energy distribution application, the electrical signals emitted by the generator are more particularly wave streams. In direct current, they may take any other form.
For example, in the European patent granted under the number EP 0 710 051, there is provision for using a method which, by successive slippages of wave streams relative to each other, enables, at the end of a certain number of modulation periods, convergence toward a more regular distribution of the instantaneous power emitted by the generator to supply the electrical loads.
According to the above patent, the calculations to be effected to converge toward this best temporal distribution of the wave streams are simple, but at the cost of a convergence that is slow.
Thus it is preferable to use methods the convergence whereof is fast, or even instantaneous. This is for example the case of the method used by the energy distribution system marketed by the company Eurotherm Automation for more than twenty years under the name “483”. That system effects a temporal distribution of the electrical signals emitted by the generator in a modulation period in accordance with a distribution criterion determined as a function of the electrical signals and applied successively to each electrical signal in this same modulation period. More precisely, the distribution criterion is linked to the number of electrical signals to be distributed in the modulation period, that is to say to the number of electrical loads that have to be supplied with energy during that modulation period. According to this criterion, the modulation period is divided into as many time intervals of the same length as there are electrical signals to be transmitted and the rising edge of an electrical signal is transmitted at the beginning of each interval. The consequence of this is a regular temporal distribution of the rising edges of the electrical signals to be emitted.
As a result of this, a relatively good temporal distribution of the electrical signals emitted by the generator is obtained instantaneously, that is to say in a single modulation period. Nevertheless this distribution is not the optimum distribution.
The invention aims to remedy the limitations of the existing methods, and in particular to improve the method implemented by the “483” system, by providing a method of determination of an energy distribution using a more refined distribution criterion.